Torsion zone to absorb torque peaks to avoid breakage. 10 times life expectancy versus standard bits. For impact driver, drill and screwdriver..1” T30 impact torx bits 50pcs. Nice choice for replacement..CNC machined tips, S2 alloy steel body, hardened core to increase bit strength and reduce fracture. Manganese Phosphate surface to prevent rust..Widely used in home repairs, automobiles, woodworking and other screw driving applications..All day after-sale service. If you have any questions, please contact us via amazon. Thanks for choosing toolant.